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Chapter 6 Special Depositional Environments
SAL T STRUCTURES, SOUTHERN RED SEA
ANTICUNAL ZONE
CANOPY ZONE
ROLLER ZONE
HALF GRABEN
SALT CANOPY , ISOLATEO
e
CONTRACTION
OVER THIN SAL T
I
EXTENSION
OVER THIN SAL T
STEP?
EXTRUSION OF DIAPIRS
d
SW
(OVER CONTRTACTING AREASI
NE
INITIAL SAL T DEPOSIT
SALT STRUCTURES, GULF OF MEXICO
WITHDRAWAL SYNCLlNE
a
Fig. 6.17. a-c Formation of allochthonous salt sheets
(canopies) via diapirs and salt wedges thrust over
younger strata. Salt sheets may become isolated by
downdip gravitational spreading and overly younger
reservoir sands. Withdrawal of salt in the underground creates thin-skinned fault systems, synclines
and graben structures (see also 1). (Based on observaDOWNDIP SPREADING
tions in the Gulf of Mexico, after Montgomery and
Moore 1997). d-f Various salt structures in the
southem Red Sea, controlled by the thin-skinned tectonic regime over the primary salt deposit, i.e., extension over thin or thick salt, and contraction. Canopy
zone evolves over thick primary salt. (After Heaton
et al. 1995, modified)